Semiconductor device and a method of manufacturing the same
AssigneeRenesas Electronics Corporation
InventorsKatsuhiko Hotta, Kyoko Sasahara
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Abstract
For simplifying the dual-damascene formation steps of a multilevel Cu interconnect, a formation step of an antireflective film below a photoresist film is omitted. Described specifically, an interlayer insulating film is dry etched with a photoresist film formed thereover as a mask, and interconnect trenches are formed by terminating etching at the surface of a stopper film formed in the interlayer insulating film. The stopper film is made of an SiCN film having a low optical reflectance, thereby causing it to serve as an antireflective film when the photoresist film is exposed.
Claims11
A semiconductor device, comprising:
- (a) a first interlayer insulating film formed over a main surface of a semiconductor substrate;
- (b) a first via hole formed in the first interlayer insulating film;
- (c) a first interconnect trench formed in the first interlayer insulating film and connected with the first via hole;
- (d) a first interconnect formed by filling a first metal in the first interconnect trench and the first via hole;
- (e) a first barrier insulating film formed on the first interconnect;
- (f) a second interlayer insulating film formed over the first barrier insulating film;
- (g) a second via hole formed in the second interlayer insulating film;
- (h) a second interconnect trench formed in the second interlayer insulating film and connected with the second via hole;
- (i) a second interconnect formed by filling a second metal in the second interconnect trench and the second via hole;
- and
- (j) a second barrier insulating film formed on the second interconnect,
- wherein the second interlayer insulating film has an etching stopper film,
- wherein the etching stopper film is arranged nearer to a bottom surface of the second interconnect trench than to a top surface of the second interconnect,
- wherein the first interlayer insulating film has no etching stopper film formed therein,
- wherein the second interlayer insulating film is thicker than the first interlayer insulating film,
- wherein a depth of the second interconnect trench is greater than a depth of the first interconnect trench,
- wherein a depth of the second via hole is greater than a depth of the first via hole, and
- wherein a diameter of the second via hole is greater than a diameter of the first via hole.
Dependencies are inferred from the claim text.